Manufacture of manganese in low-stack blast furnace



Aug. 19, 1958 P. TARDIEU MANUFACTURE OF MANGANESE IN LOW-STACK BLAST FURNACE Filed July 23, 1957 m m m g CARBON LINING g CHARGING MEANS LEVEL OF CHARGE.

SHEET METAL GROUND United States Patent Dfifice MANUFACTURE OF MANGANESE IN LOW-STACK BLAST FURNACE Pierre Tardieu, Edea, Cameroun, Africa, assignor to Pechiney, Compagnie de Produits Chimiques et Electrornetallurgiques, Paris, France, a corporation of France Application July 23, 1957, Serial No. 673,657 Claims priority, application France July 31, 1956 5 Claims. (Cl. 7580) areas where electric power is lacking.

The process which is the object of the present invention, makes it possible to obtain a metal responding to the following analysis:

Percent Manganese 89 to 92 Iron l to 3 Silicon 0.10 to 0.50 Carbon 6.5 to 7 Sulfur, phosphorous Traces In the process according to the invention, there can be used a powdered pyrolusite which has been enriched, for example, by a flotation process and possesses the following composition:

Percent Manganese (as MnO 60 to 62 Iron (as Fe O l to 1.5 Silica (gangue) 2 to 3 This ore is agglomerated into balls by means of an organic binder, for example, manioc.

The reducing agent can be anthracite, wood charcoal, or any kind of coke, preferably with a low iron content. In order to obtain the highest manganese content, there can be used, for example, pitch coke or pechcoke having an ash content of 0.5-0.6%.

The blast blown into the low-stack blast furnace can be oxygen, or air containing 45 to 70% oxygen. It is possible to preheat the blast, for example, by using the gas which is evolved at the top of the furnace. However, a cold blast can also be blown.

In a preferred embodiment of the invention, the charge is made up of ore and reducing carbon, without addition of any element designed to form a slag. Hence, the latter can only come from the gangue of the ore or from the ashes of the fuel, and only amounts to some tens of kilograms per ton of manganese produced.

The manganese yield exceeds 70% and, frequently, attains 75 to 80%.

The silica contained in the charge is almost entirely 2,848,318 Patented Aug. 19, 1958 present invention, and are given by way of illustration and not by way of limitation. I I

The furnace used in carrying out the operation coma diameter of 1 meter at the level of the tuyeres 2, and a working height of 3 meters above the same level. Into this low-stack blast furnace there was introduced a smelting charge having the following composition per ton of metal produced: Pitch coke (pechcoke) kg 2300 Pyrolusite balls kg 2250 oxygen content cu. m 4000 There was obtained with a manganese yield of 77%,. a metal having the following composition:

Percent Manganese 92 Carbon 6.8 Iron 1 Silicon 0.2

There were collected about 50 kilograms slag per ton of metal.

In the case of the usual blast furnaces of industrial see, there is observed an increase in coke consumption would scarcely amount to the minimum consumption obtained in a (high) blast furnace. It is quite certain that by using the process according to the invention in a low-stack blast furnace having a diameter of 2 meters or 2.50 meters at the level of the tuyeres, the fuel consumption decreases enormously.

Moreover, it would have been expected that the manganese losses in the gases would be considerable by reason of the relative volatility of the metal and the low height The term cold blast as used in the specification and claims denotes a blast at ambient or normal temperatures.

of silicon, sulfur and iron.

The low silicon content is the more remarkable because the process does not require the use of an ore particularly low in silicon. It follows that the managanese carbide produced by a low-stack furnace can have wider application than the ferromanganese obtained in the usual blast furnace or in an electric furnace, or manganese carbide obtained by electrothermic process, especially, where it is important to have a low content of iron and silicon and particularly, in the case of alloys of non-ferrous metals having an aluminum, copper, chromium, nickel, etc. base.

I claim:

11- Emma fe reat n s l c -c nta n ng man an o e mespr in th tep Q tre t n a h r of s m nganese ore and carbonaceous material ina low-stack blast furnace witha blast of oxygen-enriched air, whereby the ore is reduced to produce a'high-grade managanese metal of low silicon content, and recovering said manganese metal.

Zx'The method of smelting a silica-containing manganese ore to produce a high-grade manganese product of low silicon content and containing not less than 89%. manganese, comprising the steps of: charging a mixture consistingof the said manganese ore and a carbonaceous reducing material into a low-stack-blast furnace; blast- 4 ing the charge with oxygen-enriched air, whereby the ore is reduced to produce the aforesaid high-grade manganese product, and recovering said manganese product. 3. The process of claim 2, wherein the ore is an enriched manganese concentrate in finely divided state.

4. The process of claim 2, wherein the blast has an oxygen content of 45 to 70%.

5. The process of claim '2, wherein a cold blast is used.

References Cited in the file of this patent U. S. Bureau of Mines, Report of Investigations, No. R. I. 3477, Manganese and Its Alloys (1939). (47 pages, page 5 relied on.)

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,848,318 August 19, 1958 Pierre Tardieu It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 40, for "such-grade) read such high-grade (SEAL) Attest:

KARL H AXLINE Attesting Oflicer ROBERT C. WATSON Commissioner of Patents 

1. PROCESS FOR TREATING SILICA-CONTAINING MANGANESE ORES COMPRISING THE STEPS OF: TREATING A CHARGE OF SAID MANGASNESE ORE AND CARBONACEOUS MATERIAL IN A LOW-STACK BLAST FURNACE WITH A BLAST OF OXYGEN-ENRICHED AIR, WHEREBY THE ORE IS REDUCED TO PRODUCE A HIGH-GRADE MANAGENESE METAL OF LOW SILICON CONTENT, AND RECOVERING SAID MANAGANESE METAL. 